Available for full-time remote · UTC+7 (Vietnam)

Sergey
Krinitsyn.

AI Product Engineer building end-to-end products — from FastAPI backend and LLM pipeline to production deploy. React · Python · LLM · 10+ shipped products across PropTech, AI content, and marketing automation.

React 18 Python · ffmpeg LLM · OpenAI · Anthropic Firebase Growth/Marketing eng.
Get in touch → See projects
Sergey Krinitsyn
Nha Trang, Vietnam · open to relocation
01 / About
↳

I'm an end-to-end product engineer. I take an idea from "we need this feature" to a live product without handoffs: design → frontend → backend → AI logic → marketing automation.

Over the last year I built and shipped five production products in PropTech and AI content: a SaaS for real estate developers, a multi-role broker CRM, an autonomous AI content engine, and a text-to-video generator for marketing.

My edge is the combination of AI engineering, modern frontend, and a product/growth mindset — not "another React dev," not "another ML researcher." I care about what ships, what users do with it, and what it costs to run.

02 / Stack
↳

AI / LLM

  • OpenAI, Anthropic Claude
  • NVIDIA NIM (Llama), Google Gemini
  • Prompt engineering, cascade fallbacks
  • RAG patterns, structured outputs
  • Cost-optimized multi-model pipelines

Frontend

  • React 18, Vite, TypeScript
  • Tailwind CSS, Framer Motion
  • Three.js / React-Three-Fiber
  • React Router 7, PWA, SEO prerender
  • Performance: chunks, lazy-load, prerender

Backend

  • Node.js 20, Firebase Cloud Functions
  • Firestore (deep subcollections, security rules)
  • Firebase Auth + custom claims, multi-tenant
  • REST APIs, webhooks, Google Sign-In

Python

  • Python 3, ffmpeg, Pillow
  • Flask, BeautifulSoup, requests
  • Firebase Admin SDK
  • systemd services, cron pipelines
  • Video composition · Ken Burns · captions

Marketing Eng.

  • Yandex.Direct API, Yandex.Metrika
  • Google Search Console
  • n8n, Telegram Bot API, VK API
  • YouTube Data API v3
  • SEO automation, growth pipelines

DevOps / Tools

  • Git, GitHub, Firebase CLI
  • Ubuntu, systemd
  • Playwright (E2E), Vitest
  • MCP servers for AI agents
03 / Projects
↳

Selected work.

Eight products I built solo or as the lead engineer — across growth automation, AI content, PropTech SaaS, and paid Telegram bots. Each is live in production (or has been). Detail on stack, scope, and role inside each card.

Featured · Growth Automation 2025–2026 · live

eDaru.su

A full-cycle growth-automation platform for a courier referral business. SEO landing + backend + bot + workers. Auto-generated SEO content via Gemini, ad campaign management through the Yandex.Direct API, analytics via Yandex.Metrika, autoposting to Telegram and VK, lead capture through a bot. Seven custom MCP servers wire the whole stack into an AI-agent loop — Yandex.Direct, Yandex Webmaster, GSC, YouTube, VK, Click.ru, custom Telegram publisher.

React 18 · Vite Firebase Functions Gemini API Yandex.Direct API Yandex.Metrika Google Search Console VK · Telegram · YouTube APIs MCP servers ×7
Role
Solo full-stack + growth eng.
Scope
Landing → backend → bot → ads
Outcome
Marketer + SEO + SMM as one pipeline
Featured · AI Video Pipeline 2025–2026

Broker Reels Studio

A Python pipeline that turns a real estate listing into a TikTok/Reels-style short video. LLM writes the script, the image module picks visuals, ffmpeg composes the video with Ken Burns motion, smooth text animation, and music. Triggered from the broker dashboard via a Cloud Function. Replaces a marketer/SMM specialist for small agencies.

Python ffmpeg Pillow Flask OpenAI / Anthropic Firebase Functions Telegram Bot API
Role
Sole owner
Scope
Concept → architecture → deploy
Outcome
Replaces SMM specialist hours
Production SaaS 2025

AxonLeads

SaaS for real estate developers: project ingestion, unit-grid with ROI, generated PDF presentations, multi-role auth (superadmin / developer / broker / client), investor portal with unlock logic and AI price-list parsing.

React 18 Vite Firestore Cloud Functions jsPDF
~127K LOC · solo full-stack · live in production
AI Automation 2025

daily-poster

A daemon that, once a day, picks a topic, writes a post via NVIDIA Llama, generates an illustration via Gemini Image, composes a final card in Pillow, and publishes to Telegram and VK. Cost-optimized cascade — cheap models for scoring, expensive only for the final pass.

Python NVIDIA NIM Gemini systemd Telegram/VK API
Autopilot · Ubuntu server · zero-touch publishing
Multi-role CRM 2025–2026

BrokerOS

CRM with three roles (agent / broker / admin): leads, listings, shareable "rooms" for clients, conversion analytics, AI matcher for client briefs. Firestore security rules with tenant isolation, real-time via onSnapshot.

React Firestore rules Cloud Functions Custom claims
Multi-tenant · data architecture + frontend + AI
Mobile-first UX 2025

ClientRoom

A TikTok-style listing showcase. Vertical feed (Reels-style), Framer Motion animations, lazy-loaded chunks, view analytics, shareable broker links. Performance work: prerender, code-splitting, image optimization.

React Framer Motion Vite chunks Dynamic imports
UX-first · design + implementation
Production Python backend 2025

EnergyBot

Paid Telegram bot for consultations. FastAPI + SQLAlchemy backend, GPT-4o-mini dialogs with caching, Telegram Stars payments, APScheduler for broadcasts, an admin CRM bot for stats and content management. Custom MCP server for Telegram publishing.

FastAPI SQLAlchemy OpenAI APScheduler Telegram Stars
Live · payments · GPT-4 dialogs · admin CRM
B2B portal + Mini Apps 2025–2026

Agnis Portal

Consultation booking portal + Gemini AI assistant + financial charts + Sanity CMS + Telegram Web App SDK. Netlify Functions backend, real-time data, Framer Motion.

React 19 Telegram Mini App SDK Gemini API Sanity CMS Netlify Functions
Mini App · AI assistant · booking flow
Also worked on
· 7+ custom MCP servers (Click.ru, Y.Direct, Y.Webmaster, GSC, YouTube, VK, TG)
· Tochka Bank API · monthly P&L automation · Bybit card tracking
· Scraping pipelines (FazWaz, DotProperty, Bayut, YouTube, VK)
· "Warm precision luxury" design system across 5+ products
· Investor portal with PDF unlock logic
· Telegram bots: osteo_stars, bali-bot, maxbotcur, daily-poster, oracle-admin
· SEO automation: prerender + sitemap + GSC pipelines
· Game experiments (Phaser, Three.js): GTA-style courier mini-game
· Several landing pages: alchimia, neuro-sales, kostya-markirovka, bali-listings
04 / What I want
↳

Full-time remote, in a team that ships.

I'm looking for full-time remote employment — W-2, contractor, or via EOR. Timezone UTC-2 .. UTC+5 works best. Open to relocating to Serbia, Armenia, UAE, or the EU.

Target roles: AI Product Engineer · AI Solutions Engineer · Senior Full-stack (React + Python + LLM) · Growth/Marketing Engineer with AI focus · Product Engineer at a PropTech / B2B SaaS startup.

Languages
Russian (native)
English (B1-B2, improving)
Workstyle
Async-friendly
Long focus blocks
Available
Immediately
Full-time only
05 / Contact

Let's talk.

Best way to reach me — email. I reply within 24 hours, even from Vietnam.

sergeykrin98@gmail.com → GitHub ↗ LinkedIn ↗
Location: Nha Trang, Vietnam
Timezone: UTC+7
Status: available
Resume (English) ↓ · Резюме (Русский) ↓